Kate Middleton hinted she was having a girl during a March 5 appearance at the National Fishing Heritage Centre in Grimsby, England, and said “I’ll take that for my d–” and then stopped herself. (SplashNews)

Jessica Simpson revealed she was having a boy on “Jimmy Kimmel Live” on March 6 when she accidentally said she “never knew a wiener could make me nauseous.” (Courtesy of ABC)

Kathie Lee Gifford accidentally told viewers on the fourth hour of ‘Today’ that her close family friend Kim Kardashian is pregnant with a girl. (Courtesy of NBC, FameFlynet)

Holly Madison’s baby daddy Pasquale Rotella let the cat out of the bag when he tweeted that he missed his “girls,” prompting Holly to make the official announcement on twitter soon after. (Getty, Courtesy of Twitter)

Kristen Bell let is slip on the “The Ellen Degeneres Show” that her baby daddy Dax Shepard wouldn’t wait to off road with the baby, prompting Ellen to grill her about it being a boy. (Courtesy of NBC)

During a November 2005 appearance on “The Tonight Show,” Jennifer Garner accidentally said “she” when referencing her baby when she was pregnant with her first daughter Violet. She had wanted to keep it a secret. (Courtesy of NBC)